A feeding device for a multi-color 3D printer and a printer thereof

Abstract

The present application relates to a kind of feed device for multi-color 3D printer and its printer.The feed device includes feed cylinder, heating mechanism, stirring mechanism, multiple image acquisition modules and controller.The side wall of feed cylinder is provided with multiple transparent observation windows in circumferential array near the bottom.Heating mechanism is arranged on feed cylinder and is used to heat cavity.Stirring mechanism is arranged on feed cylinder and is used to stir the heating molten wire in cavity.The acquisition direction of image acquisition module is directly opposite the acquisition point in the center of corresponding transparent observation window, and is used to acquire the wire image at the acquisition point.Controller calculates the color difference of any two acquisition points according to the color information in wire image, calculates the real-time mixing uniformity of wire according to each color difference value, to judge whether wire meets output requirements, to ensure that the molten color mixing of mixed multi-color wire is more uniform, reduce the mixed color phenomenon in molten wire input to printing head, improve the quality of printing finished product.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and in particular to a feeding device for a multicolor 3D printer and the printer thereof. Background Technology

[0002] Color 3D printing technology has become a new trend in the development of additive manufacturing technology. Currently, 3D printers on the market use monochrome or traditional extrusion methods, relying on single-strand filaments, making it difficult to achieve multi-color output.

[0003] Chinese utility model patent with authorization announcement number CN212603439U discloses a melting and mixing device for 3D printing. During the melting and mixing of different pigments, the device simultaneously stirs, mixes, and heats the pigments of different colors to improve the fusion degree between the pigments of different colors. At the same time, it can collect the color information of the mixed pigments and automatically adjust the melting and mixing process of different pigments based on the color information, and automatically adjust the mixed color.

[0004] While the above technology can provide raw materials of various colors for multi-color 3D printers, the mixing and stirring process of the filaments is limited by the space and time required for mixing. As a result, the molten filaments of different colors are prone to uneven mixing, which leads to the appearance of mixed colors in the molten filaments ejected from the print head and affects the quality of the printed product. Summary of the Invention

[0005] Based on this, it is necessary to address the technical problem in existing multicolor 3D printing where uneven mixing of molten colors easily occurs, resulting in impurities in the molten filament ejected from the final printing nozzle and reducing the quality of the printed product. The present invention provides a feeding device and printer for a multicolor 3D printer.

[0006] This invention discloses a feeding device for a multi-color 3D printer, comprising: a feeding cylinder, a heating mechanism, a stirring mechanism, multiple image acquisition modules, and a controller.

[0007] The feed cylinder has a hollow interior. A feeding assembly is located at the top of the feed cylinder to feed one or more specific colors of filament into the cavity. Multiple transparent observation windows arranged in a circular array are located on the side wall of the feed cylinder near the bottom. A discharge pipe communicating with the cavity is located at the bottom of the feed cylinder, and an electric valve is installed on the discharge pipe.

[0008] The heating mechanism is installed on the feeding cylinder and is used to heat the cavity.

[0009] The stirring mechanism is installed on the feeding cylinder and is used to stir the heated and melted wire inside the cavity.

[0010] The plurality of image acquisition modules correspond to the plurality of transparent observation windows respectively. The acquisition direction of each image acquisition module is directly opposite to the acquisition point in the center of the corresponding transparent observation window, and is used for acquiring the filament image at the acquisition point.

[0011] The controller is configured to: (a) obtain target printing information, and obtain target color parameters according to the target printing information; (b) control the feeding assembly to input a preset amount of one or more color filaments into the cavity according to the target color parameters; (c) control the heating mechanism and the stirring mechanism to stir and heat the filaments in the cavity, and after a preset stirring and heating time, acquire filament images at a plurality of acquisition points at the same time, and calculate color differences ΔE between any two acquisition points in the plurality of acquisition points according to color information in the filament images; calculate real-time mixing uniformity of the filaments in the feeding barrel according to the color differences; (d) determine whether the real-time mixing uniformity is within a preset expected uniformity threshold; if yes, stop stirring and heating, and control the electric valve to open and discharge the mixed and uniform molten filaments; otherwise, continue stirring and heating until the real-time mixing uniformity meets the requirements.

[0012] The feeding device can more comprehensively monitor the bottom of the cavity by arranging the plurality of transparent observation windows and the image acquisition modules along the circumference of the bottom of the feeding barrel, calculate color differences between any two acquisition points according to color information in the acquired filament images, and calculate real-time mixing uniformity of the filaments at the bottom of the feeding barrel according to the color differences, so as to determine whether the filaments meet the output requirements, thereby ensuring that the molten color mixing of the mixed filaments of multiple colors is more uniform, reducing the color mixing phenomenon in the molten filaments input to the printing nozzle, and improving the quality of the printing products

[0013] As a further improvement of the above scheme, the calculation formula of the real-time mixing uniformity is as follows:

[0014]

[0015] In the formula, n is the number of combinations of two observation windows taken from all the transparent observation windows. The color difference ΔE is calculated according to the following formula: L, a and b represent the differences in gray scale, red and blue channels respectively.

[0016] As a further improvement of the above scheme, the transparent observation windows are arranged in a circular array along the side wall of the feeding barrel.

[0017] As a further improvement of the above scheme, the feeding device further comprises:

[0018] The light shielding assembly is fixedly connected to the side wall of the feeding barrel near the bottom, and is used to provide a light-shielded closed environment for the image acquisition module and the transparent observation window.

[0019] As a further improvement of the above-mentioned scheme, the light shielding assembly comprises a sleeve ring and a box body. The sleeve ring is fixedly sleeved on the feeding cylinder. The number of the box bodies corresponds to the number of the image acquisition modules, and the box bodies are integrally fixedly connected with the sleeve ring.

[0020] As a further improvement of the above-mentioned scheme, the light shielding assembly comprises a sleeve ring and a box body. The sleeve ring is fixedly sleeved on the feeding cylinder. The number of the box bodies corresponds to the number of the image acquisition modules, and the box bodies are integrally fixedly connected with the sleeve ring.

[0021] As a further improvement of the above-mentioned scheme, the light shielding assembly comprises a sleeve ring and a box body. The sleeve ring is fixedly sleeved on the feeding cylinder. The number of the box bodies corresponds to the number of the image acquisition modules, and the box bodies are integrally fixedly connected with the sleeve ring.

[0022] As a further improvement of the above-mentioned scheme, the light shielding assembly comprises a sleeve ring and a box body. The sleeve ring is fixedly sleeved on the feeding cylinder. The number of the box bodies corresponds to the number of the image acquisition modules, and the box bodies are integrally fixedly connected with the sleeve ring.

[0023] As a further improvement of the above-mentioned scheme, the light shielding assembly comprises a sleeve ring and a box body. The sleeve ring is fixedly sleeved on the feeding cylinder. The number of the box bodies corresponds to the number of the image acquisition modules, and the box bodies are integrally fixedly connected with the sleeve ring.

[0024] The application also discloses a multi-color 3D printer comprising the feeding device.

[0025] Compared with the prior art, the technical scheme disclosed by the application has the following beneficial effects:

[0026] 1. The feeding device can more comprehensively monitor the bottom of the cavity by arranging the plurality of transparent observation windows and the image acquisition modules along the circumference of the bottom of the feeding cylinder, and can calculate the color difference between any two acquisition points according to the color information in the collected filament image, so as to calculate the real-time mixing uniformity of the filament at the bottom of the feeding cylinder according to each color difference value, thereby judging whether the filament meets the output requirements, and further ensuring that the melting and color mixing of the mixed multi-color filament is more uniform, reducing the mixed color phenomenon in the melted filament input to the printing nozzle, and improving the quality of the printing product.

[0027] 2. The 3D printer has the same beneficial effects as the feeding device, and details are not repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 FIG. 1 is a schematic view of the three-dimensional structure of a multi-color 3D printer according to an embodiment of the application;

[0029] Figure 2 FIG. 4 is a schematic view of the three-dimensional structure of the feeding device for the multi-color 3D printer in the application; Figure 1

[0030] FIG. 4 is a schematic view of the three-dimensional structure of the feeding device for the multi-color 3D printer in the application;Figure 3 for Figure 2 A three-dimensional structural diagram of the central feeding device with the light-shielding components concealed.

[0031] Figure 4 for Figure 3 Cross-sectional view of the feeder;

[0032] Figure 5 for Figure 3 A three-dimensional structural diagram of the internal structure of the feeding device;

[0033] Figure 6 for Figure 2 Top view of the central shading component.

[0034] Explanation of main component symbols

[0035] 1. Feeding device; 11. Feeding cylinder; 110. Cavity; 111. Transparent observation window; 112. Discharge pipe; 113. Electric valve; 12. Heating mechanism; 13. Stirring mechanism; 131. Drive motor; 132. Rotating rod; 133. Stirring blade; 14. Image acquisition module; 140. Support; 15. Light shielding component; 151. Collar; 152. Box body; 2. Frame; 3. Printing nozzle; 4. Printing platform; 5. Drive device.

[0036] The above description of the main component symbols, together with the accompanying drawings and specific embodiments, provides a more detailed explanation of the present invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] Please see Figure 1 This embodiment provides a multi-color 3D printer, which includes a feeding device 1, and may also include a frame 2, a print head 3, a printing platform 4, and a drive device 5. The drive device 5 drives the print head 3 to perform additive manufacturing on the printing platform 4, and the frame 2 is used to mount various printing structures. The feeding device 1 can be fixedly connected to the drive device 5 and can move together with the print head 3. In some embodiments, the feeding device 1 can be fixedly connected to the frame 2 and communicates with the print head 3 via a flexible hose. The structural principles of the frame 2, print head 3, printing platform 4, and drive device 5 are not considered inventive points of this embodiment and will not be described in detail here.

[0041] Please see Figures 2 to 5 The feeding device 1 includes: a feeding cylinder 11, a heating mechanism 12, a stirring mechanism 13, multiple image acquisition modules 14 and a controller (not shown), and may also include a light-shielding component 15.

[0042] The feed cylinder 11 has a hollow cavity 110 inside. A feeding assembly (not shown) is provided at the top of the feed cylinder 11. The feeding assembly is used to input one or more specific colors of filament into the cavity 110. A filament feeding structure commonly used in the field of 3D printing technology can be adopted. The filament color can be three (red, yellow, and blue), or black and white can be added. Other colors of filament can also be added, as long as it is convenient to mix colors.

[0043] The side wall of the feeding cylinder 11 near the bottom is provided with a plurality of transparent observation windows 111 arranged in a circumferential array. In this embodiment, four transparent observation windows 111 are arranged in a circumferential array along the side wall of the feeding cylinder 11. Of course, in other embodiments, the number of transparent observation windows 111 can be set to more, or the transparent observation windows 111 can be set as annular windows, which are coaxially embedded in the feeding cylinder 11.

[0044] The bottom end of the feed cylinder 11 is provided with a discharge pipe 112 that communicates with the cavity 110, and an electric valve 113 is provided on the discharge pipe 112. The end of the discharge pipe 112 away from the cavity 110 can be connected to the print head 3 of the 3D printer through a flange.

[0045] A heating mechanism 12 is mounted on the feeding cylinder 11 and used to heat the cavity 110. In this embodiment, the heating mechanism 12 can be fixed to the inner wall of the feeding cylinder 11 and arranged as a group along the axial direction of the feeding cylinder 11. Of course, in other embodiments, the number of heating mechanisms 12 can be increased according to the axial length of the feeding cylinder 11 and the target heating effect. The heating mechanism 12 may include a resistance wire housed in a housing, which is heated by electricity. The housing is made of a thermally conductive material, and the structure of the housing does not interfere with the stirring mechanism 13 or the wire in the cavity 110.

[0046] A stirring mechanism 13 is mounted on the feeding cylinder 11 and is used to stir the heated and molten filaments within the cavity 110. In this embodiment, the stirring mechanism 13 may include a drive motor 131, a rotating rod 132, and stirring blades 133. The drive motor 131 is bolted to the center of the top end of the feeding cylinder 11. The rotating rod 132 is coaxially mounted inside the feeding cylinder 11, and the top end of the rotating rod 132 is coaxially fixed to the output shaft of the drive motor 131. Multiple stirring blades 133 are fixedly mounted on the bottom end of the rotating rod 132, and the multiple stirring blades 133 are at the same height as multiple transparent observation windows 111, thus enabling direct stirring of the molten filaments at the bottom of the cavity 110.

[0047] Multiple image acquisition modules 14 correspond to multiple transparent observation windows 111, and can be CCD cameras. Each image acquisition module 14 is aligned with the acquisition point at the center of the corresponding transparent observation window 111, and is used to acquire an image of the filament at that acquisition point. In this embodiment, each image acquisition module 14 is equipped with a bracket 140, and the bracket 140 is fixed to the outer wall of the feeding cylinder 11 by bolts. Four groups of image acquisition modules 14 can be configured. However, in some embodiments, the number of image acquisition modules 14 can be increased according to the requirements of color accuracy, thus enabling more comprehensive monitoring of the bottom of the cavity 110 and making subsequent calculation results more accurate and reliable.

[0048] Please see Figure 6 The light-shielding assembly 15 is fixedly connected to the side wall of the feeding cylinder 11 near the bottom and provides a light-shielding, sealed environment for the image acquisition module 14 and the transparent observation window 111. Specifically, the light-shielding assembly 15 may include a collar 151 and four housings 152. The collar 151 is fixedly sleeved on the feeding cylinder 11. The number of housings 152 corresponds to the number of image acquisition modules 14, and the housings 152 are integrally fixedly connected to the collar 151. Each housing 152 may be equipped with a supplementary light, which can provide uniform illumination to the acquisition points of each transparent observation window 111. Of course, in some embodiments, the image acquisition module 14 may have a built-in supplementary light unit.

[0049] The controller is used for:

[0050] (a) Obtain the target printing information and obtain the target color parameters based on the target printing information.

[0051] (b) Control the feeding assembly to input one or more colored filaments of a preset amount into the cavity 110 according to the target color parameters.

[0052] (c) The heating mechanism 12 and the stirring mechanism 13 are controlled to stir and heat the filament material in the cavity 110. After a preset time period of stirring and heating, images of the filament material at multiple sampling points at the same time are acquired. The color difference ΔE between any two sampling points is calculated based on the color information in the filament material images. The real-time mixing uniformity of the filament material in the feeding cylinder 11 is calculated based on each color difference. The formula for calculating the real-time mixing uniformity is as follows:

[0053]

[0054] In the formula, n represents the number of combinations of taking two observation windows from all transparent observation windows 111. In this embodiment, n is 6. For example, if the four observation windows are numbered A, B, C, and D, then the combinations of taking two from them are AB, AC, AD, BC, BD, and CD, corresponding to six sets of color difference data. L, a, and b represent the differences in the grayscale, red, and blue channels, respectively.

[0055] (d) Determine whether the real-time mixing uniformity is within a preset desired uniformity threshold. If yes, stop stirring and heating, control the electric valve 113 to open and discharge the uniformly mixed molten filament. Otherwise, continue stirring and heating until the real-time mixing uniformity meets the requirements. In some embodiments, the preset time period for re-stirring and heating can be gradually shortened with each repetition to a minimum time period.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A feeding device for a multi-color 3D printer, characterized in that, include: The feeding cylinder has an internal cavity; a feeding assembly is provided at the top of the feeding cylinder for feeding one or more specific colors of filament into the cavity; multiple transparent observation windows are arranged in a circular array on the side wall of the feeding cylinder near the bottom; and an outlet pipe communicating with the cavity is provided at the bottom of the feeding cylinder, and an electric valve is provided on the outlet pipe. A heating mechanism is disposed on the feeding cylinder and used to heat the cavity; A stirring mechanism is provided on the feeding cylinder and is used to stir the heated and molten wire in the cavity; Multiple image acquisition modules are provided, each corresponding to one of the multiple transparent observation windows; the acquisition direction of each image acquisition module is directly facing the acquisition point in the center of the corresponding transparent observation window, and is used to acquire the image of the filament at that acquisition point; as well as The controller is used to: (a) acquire target printing information and acquire target color parameters based on the target printing information; (b) control the feeding assembly to input a preset amount of one or more colored filaments into the cavity based on the target color parameters; (c) control the heating mechanism and the stirring mechanism to stir and heat the filaments in the cavity, acquire filament images at multiple acquisition points at the same time after a preset stirring and heating time period, calculate the color difference ΔE between any two acquisition points based on the color information in the filament images, and calculate the real-time mixing uniformity of the filaments in the feeding cylinder based on each color difference. The calculation formula for the real-time mixing uniformity is as follows: In the formula, n is the number of combinations of taking two observation windows from all transparent observation windows; color difference; L, a and b represent the differences in grayscale, red and blue channels, respectively; (d) determine whether the real-time mixing uniformity is within a preset expected uniformity threshold; if yes, stop stirring and heating, control the electric valve to open and discharge the uniformly mixed molten filament; otherwise, continue stirring and heating until the real-time mixing uniformity meets the requirements.

2. The feeding device for a multi-color 3D printer according to claim 1, characterized in that, The transparent observation windows are arranged in a circular array along the side wall of the feeding cylinder.

3. The feeding device for a multi-color 3D printer according to claim 1, characterized in that, The feeding device further includes: A light-shielding assembly is fixedly connected to the side wall of the feeding cylinder near the bottom and is used to provide a light-shielding, sealed environment for the image acquisition module and the transparent observation window.

4. The feeding device for a multi-color 3D printer according to claim 3, characterized in that, The light-shielding component includes a collar and a housing; the collar is fixedly sleeved on the feeding cylinder; the number of housings corresponds to the number of image acquisition modules, and the housings are integrally fixedly connected to the collar.

5. The feeding device for a multi-color 3D printer according to claim 3, characterized in that, Each of the aforementioned boxes is equipped with a supplementary light.

6. The feeding device for a multi-color 3D printer according to claim 1, characterized in that, The stirring mechanism includes a drive motor, a rotating rod, and stirring blades; the drive motor is fixedly connected to the center of the top end of the feeding cylinder; the rotating rod is coaxially arranged inside the feeding cylinder, and the top end of the rotating rod is coaxially fixed with the output shaft of the drive motor; multiple stirring blades are fixedly installed at the bottom end of the rotating rod, and the multiple stirring blades and multiple transparent observation windows are located at the same height.

7. The feeding device for a multi-color 3D printer according to claim 1, characterized in that, At least one heating mechanism is provided along the axial direction of the feeding cylinder.

8. The feeding device for a multi-color 3D printer according to claim 1, characterized in that, Each of the image acquisition modules is provided with a bracket, and the bracket is used to fix the image acquisition module and the feeding cylinder by bolts.

9. A multi-color 3D printer, comprising a feeding device, characterized in that, The feeding device is the feeding device as described in any one of claims 1 to 8; wherein, the end of the discharge pipe away from the cavity is connected to the print head of the 3D printer.

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